Driving and stopping mechanism



Feb. 21, 1928. 1,659,937

E. B. ALLEN DRIVING AND STOPPING MECHANISM Filed Dec. 18. 1925 4 Sheets-Sheet 1 k k INVENTOR I WIITNEZSES 1 M 1% Z AT TZJZEY Feb. 21, 1928. 1,659,937

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DRIVING AND STOPPIITG MECHANI SM Filed Dec. 18. 1925 4 Sheets-Sheet 2 T INVENTOR sa 2a).!

WITNESSES QM M ATTORNEY Feb. 21, 1928. 1,659,937

E. B. ALLEN DRIVING AND STOPPING MECHANISM Filed Dec. 18, 1925 4 Sheets-Sheet 3 WITNESS s 0W w I I ATTORNEY E. B. ALLEN muvme AND sworriue mzcaamsm Filed Dec. 18, 1925 4 Sheets-Sheet 4 Feb. 21,1928; 1,659,937

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Patented Feb. 21, 1928.

* UNITED STATES PATENT OFFICE.

EDWARD B. ALLEN, OF NEWTOXVN, CON'NE('JIICU'I, ASSIGNOR TO THE-SINGER MANU- FACTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

DRIVING AND STOPPING MECHANISM.

Application filed December 18, 1925. Serial No. 76,279.

This invention relates to mechanisms for controlling the starting and stopping of high-speed machines such,v for example, as sewing machines, which require to 'be stopped with their moving parts in a predetermined position. The problem of stopplication of parts making them costly to .c

unreliable for day-in and day-out operation. Still others subject the parts to destructive shock soon resulting in breakage and failure to operate.

The present invention has for an object to provide simple and reliable driving and stopping mechanism which will quickly bring the parts of a high speedmachine to rest at a predetermined position without destructive shock.

There are already available stop-motion devices of a simple and reliable character which will bring the parts of a machine, such as a sewing machine, to rest without destructive shock, where the running speed of the machine is not too high. Present day demands, however, require higher machine speeds and the simple stop-motions which were satisfactory at the lower speeds will not stand up under the higher speed operating conditions. According to the present improvement, means of a simple nature are provided for disconnecting the machine from its source of power at a' predetermined and preferably variable time prior to the throwing in of a positive stop, so that dur-' ing the interval between the throwing off of the power and the throwing in of the positive stop, the machine will slow down to a suitable moderate speed so that the parts can be positivelybrought to rest at the desired predetermined position without destructive shock. Use is preferably made of two tripping points, one of which operates to throw off the power and the other of which operates subsequently to throw in the positive stop. The mechanism is also preferably constructed so that a single starting connection operates to throw out the positive stop and throw on the power substantially simultaneously.

The invention is disclosed as embodied in an automatic buttonhole sewing machine of the type described in my copending applica tion Serial, No. 58,778, filed Sept. 26. 1925.

Machines of this type are designed to sew straight as distinguished from eyelet end buttonholes and comprise stitch-formmg mechanism including an upper laterally jogging needle and a lower shuttle mecharanged to cut the buttonhole-slit subsequent to sewing.

In the accompanying drawings, Fig. 1 is a side elevation, partly in section, of a buttonhole sewing machine embodying the invention. Fig. 2 is a bottom plan view of the machine. Fig.3 is a rear end elevation. Fig.4 is a transverse sectional view through the bracket-arm and bed looking toward the bracket-arm standard. 5 is a fragmentary rear side elevationof the machine showing parts of the stop-mechanism. Fig. 6 is a horizontal section through the bracketarm standard showing parts' of the stop mechanism in plan. Fig. 7 is a side elevation of the parts. of the stop-mechanism shown in Fig. -6. Fig. 8 isa section on the line 8-8, Fig. 6, and Fig. 9 is a fragmentary plan view of the controlling wheel showing the adjustable feature of the tripping point carried thereby. A

The following detailed description is for the purpose of disclosing a specific embodiment of the invention and is not to be construed in a limiting sense. t

The machine, which is constructed substantially in accordance with the disclosures of my Patent No. 1,559,539, of November 3, 1925, and said copending application Serial No. 58,778. and the application of A. R. Wood, Serial No. 27,627, filed May 4, 1925, comprises a frame including the bed 1, standard 2, bracket arm 3 and head i. The stitclrforming mechanism comprises the reciprocating and laterally jogging needlebar 5 carrying the eye-pointed needle 6. The needle-bar 5 is mounted in the swinging gate 7 which is mounted on the pivot pins 8 and derives its vibratory movement through suitable connections from the main sewing shaft 9 as disclosed in my said copending application Serial No. 58,778.

The needle 6 cooperates with the usual shuttle (not shown) which is mounted in the shuttled-ace 10 and actuated by means Fig. 2, on a lateral extension 18 of which is pivotally mounted at 19, Fig. 1, the upper clamping'lever 20 carrying the clamping foot 21. The longitudinal slide-plate 17 is mounted to slide lengthwise of the machine bed in the cross-slide plate 22 which slides crosswise of the machine bed in ways 23, 23, Fig. 1. The longitudinal slide-plate is actuated by means of the usual link 24, Fig. 2, andlever 25 having a follower 26 entering the longitudinal feed-cam groove 27 in the feed-wheel 28. The cross-slide-plate is actuated by the lever 29 which is fulcrunied at 30 on the bed 1 and has a follower 31 entering the lateral feed cam-groove 32 in the feed-wheel. The shaft 33 carrying the feed-wheel 28 and an upper controlling cam wheel 34 is driven by means of a train of gears 35, from a shaft 36 which latter is given a step-by-step motion by means of the usual pin-and-star-wheel drive 37-actuated by the bevel-gear connection 38 with the main-shaft 9. By the means described the Work-holder is given the usual work-shifting movements with intermediate periods of dwell during which the needle 6 penetrates the work foreooperationwith the shuttle in the formation of stitches.

The period of action of the main-shaft 9 and parts driven thereby is controlled by the stop-motion mechanism to be described. Mounted on the main-shaft 9 are the usual loose and tight pulleys 39 and 40, respectively, for power means such as a belt 5.

The tight pulley 40 has fixed thereto the .usual stopping cam 41 having the cam-rise 42 and stop-notch 43, Fig. 3, cooperating with the upwardly spring-pressed plunger 44 carried by the tilting stop-motion lever 45 fulcrumed at 46 on the bracket 47 fixed to the machine frame. When the upper end of the stop-motion lever 45 is tilted inwardly to running position, the plunger 44 is car ried out of engagement with the cam 42, Fig. 7, and the main-shaft 9 is thus free to be driven. When the stop-motion lever 45 is released from running position it is returned to vertical or stopping position by means of the spring 48, whereupon the plunger 44 passes transversely across the low part of the cam rise 42 and is forced extending downwardly through the bed .1 v

and formed in one side with a notch 52 adapted to be entered by the spring-pressed latch-lever 53 to lock the stop-motion lever 45 in tilted or running position. The latchlever 53 carries an adjustable'trippingpoint 54 which is engaged'by a timing device or tripping point 55 on the feed=wheel at the.

end of the sewing operation to main-shaft 9 to rest. I g f p p The parts of the stop mechanism and bring .the

their mode of operation, as set forth above,-

are well known in the art. Heretofore, however, an arm 56 on the stop-motion lever 45 carried a belt-shipper fork which shifted the belt from the tight to the loose pulley simultaneously with the movement of the StOP-ll'lOtlOll lGVGl to vertical or stopping po-' sition. Consequently the machine was driven at full speed-up to a point within one half to one revolutionof the main-shaft from stopping position of such shaft. 2

According to the present improvement, in in embodiment illustrated, the power is thrown 01f by means independent of the means for throwing the stop mechanism into action. The belt-shipper fork 57 is fixed to a rod 58 slidably mounted in the spaced bosses 59 on the lever-arm 6O .fulcrumed at 61 on the standard 2; The lever 60 has an arm 62 which extends forwardly under the bracket-arm 3 and at its free end carries a tripping point 63 adapted to beengaged by a timing device or tripping'point 64 mounted on the controlling wheel 34 which runs in fixed relation with the feed-wheel 28. The tripping point 64 is adjustable circularly of the wheel 34 to vary its time of.

action on the tripping point .63 and, to this end, the wheel 34 is formed in its upper face with a circular groove 65to receive a corresponding-rib 65 on the under side ofthe block 66 carrying the tripping point 64. A screw-bolt 67 passes through an areuate slot 67, Fig. 9, in the bottom of the groove 65 in the wheel 34 and is threaded into theblook 66. By loosening the bolt 67 the block 66 and tripping point 64 may be shifted along the groove 65 to adjust the time of action of such tripping point on the lever-arm 62. i A spring 68, Fig. 1, yieldingly urges the leverarm 62 downwardly to carry the front end of the lever-arm 60 into engagement with the adjustable abutmentscrew 69. i

g The rod 58 which carries the belt-shipper fork 57 has secured thereto between the bearing bosses 59 a stop-collar 7O pressed by a fork 57 guides the belt over the loose pulley- 39. The collar 70 is in engagement with the lug 59 and the pin 7 6 is in engagement with. thetooth 74. When the main-shaft 9 is to be started, the stop-motion lever is forcibly tilted to dotted line or running position, Fig. 1, whereupon the latch-lever 53, Fig. 2, snaps into the notch 52 and locks the lever 45 in running position. In its movement to running position the pin 76 acting against-the tooth 74 on the block 73 forces the slide-rod 58 to the left, Fig. 1, thereby carrying the e belt-shipper to the left and guiding the belt onto the tight pulley. The main-shaft 9 and the connected feed and controller-Wheels 28, 34, together with the stitch-forming and work-holder mechanisms now run through their cycle of operations. When the sewing is nearing completion and at a' predetermined time, say two or three stitches prior to the end of the sewing operation, the tripping point 64, Fig. 7 tilts the lever 62, 60 to drop the latch-block 7 3 and release the pin 76, whereupon the spring 71 urges the sliderod and belt-shipper fork to dotted line position, Fig. 7, thus throwing off the power while the stop-motion lever 45 still remains in running position.

The moving parts now run under momen tum in sewing the final stitches and, in doing so. slow down to a speed which is not destructive to the positive stopping mechanism. When the machine has run under monientum for a predetermined time the tripping point 55 on the feed-wheel acts upon the latch-lever 53 to release the stop-motion lever 45 which thereupon swings to vertical position and stops the shaft 9 in the usual manner with the needle out of the work. During this movement of the lever 45 the pin 76 engages the inclined surface 75 of the block 73 and rocks the lever 60, 62, sufiiciently to enable the pin'7 6 to pass the tooth 74 which immediately rises to full line posidriven'pulley'7 8 through asuitable partial rotation clutch mechanism such as disclosed in my said Patent No.'1,559,539. Such a clutch mechanism includes a driven disk 7 9 carrying twoangularly spaced radially slid-F ableclutch dogs 80 with which the clutcl1- controlling lever 81-1cooperates to effecta coupling of the shaft 77 to the pulley 78 for a partial rotation prior to the starting of the stitch-forming mechanism and a second partial rotation after the stitch-forming mechanism has come to rest. The first partial rotation of the shaft 77 serves to close the work-clamp and during such partial rotation a cam 82 on the shaft 77 acts through the follower 83 and link 84 to tilt the stopmotion lever 45 to running position. The machine is started by means of a treadle chain connection (not shown) with the starting lever 85 which engages the clutch-com trollin lever 81 as shown in Figs. 1 and 4. Havlng thus set forth the nature of the invention, what I claim herein is 1. The combination with a driven shaft, tight and loose belt-pulleys on said shaft, a

belt, a stop-motion device including a tilting stopemotion lever, a'stop-cam on said shaft cooperating with said lever to stop said shaft in a predetermined angular position, a belt-shipper mounted for movement independently of said stop-motion lever, and means for moving saidbelt shipper to shift the belt onto the loose pulley at a predetermined time before the stop-motion lever is shifted to stopping position.

2. The combination with a driven shaft, of tight and loose belt-pulleys on said shaft, a stop-cam fixed to said shaft, a springpressed stop-motion lever, a spring-pressed plunger carried by said lever for cooperation with said stop-cam to stop the main-shaft in a predetermined angular position, a beltshipper lever, a belt-shipper carried by said lever and spring-pressed to stopping position, separate latches for detaining said st0pmotion lever and said belt-shipper in their respective running positions, and means connected to be driven by said shaft for releasing the belt-shipper lever from its latch at a predetermined time before releasing the stopmotion lever from its latch.

3. The combination with a driven shaft,

tight and loose belt-pulleys on said shaft, a

driving belt, a belt-shipper, timing ,means connected to be driven by said shaft for timing the operation of said belt-shipper in shifting the belt from the tight to the loose pulley, an automatic stop-motion device,'and a second timing means connected to run with said shaft for throwing said stop-motion device into operation at a predetermined time after the driving belt is shifted onto the loose pulley.

4. The'eombination with a driven shaft, power means for driving said shaft, a positive stop for arresting said shaft in a predetorininedangular position, controlling mechanism including a tinnng device running with the driven shaft at a reduced speed for initiating the operation of said positive stop,

and'means for interrupting driving relation between the power means and said shaft :1,

plurality of revolutions of said shaft prior to initiation of the operation of said positive stop. H

In testimony whereof, I have signed iny name to this specification.

EDWARD B. ALLEN. 

